Prepare for your Hepatitis B Profile Blood Test by following these instructions. If there is a chance that you have been exposed to HIV, hepatitis B or C then please let us know how long before taking your sample this occurred. Your sample should be taken 4 weeks after any hepatitis B exposure. Do not take biotin supplements for two days before this test, discuss this with your doctor if it is prescribed. Please let us know if you have had a hepatitis B vaccination. You should wait at least two months after your vaccination before taking this test.